1. Field of the Invention
The invention relates to a process for mixing a liquid sample to be analyzed, in which the liquid sample is placed in a sample container, particularly a cell, and is mixed by a periodic air movement.
The invention also relates to an apparatus for mixing a liquid sample to be analyzed in a sample container, particularly a cell, in which an air movement can be produced above the sample surface.
2. Description of the Related Art
In known processes and apparatuses of this type (European Patent Application No. 0 098 949 and West German Offenlegungsschrift No. 15 98 514), the sample container is sealed and the air column between the seal and the sample surface is subjected to periodic vibrations or oscillations, so that the liquid sample in the sample container is periodically oscillated and consequently mixed either by deforming an elastic container wall or by moving the sample backwards and forwards between the two legs of the U-shaped sample container, whereof one leg is sealed in the aforementioned manner and whereof the other leg is open.
Thus in the known process, it is necessary to seal the sample container in order to be able to periodically oscillate an air column above the sample surface. This is not only relatively complicated, but also leads to sealing problems. In addition, special sample containers are required, which are either U-shaped or have an elastically deformable wall.
The problem of the present invention is to provide a simple process and a simple apparatus for mixing a liquid sample to be analyzed in a standard container, with the aid of which a contact-free mixing takes place without sealing problems occurring.